Li Zhijian 66eca1021a mm/page_alloc: fix pcp->count race between drain_pages_zone() vs __rmqueue_pcplist() ... It's expected that no page should be left in pcp_list after calling zone_pcp_disable() in offline_pages(). Previously, it's observed that offline_pages() gets stuck [1] due to some pages remaining in pcp_list. Cause: There is a race condition between drain_pages_zone() and __rmqueue_pcplist() involving the pcp->count variable. See below scenario: CPU0 CPU1 ---------------- --------------- spin_lock(&pcp->lock); __rmqueue_pcplist() { zone_pcp_disable() { /* list is empty */ if (list_empty(list)) { /* add pages to pcp_list */ alloced = rmqueue_bulk() mutex_lock(&pcp_batch_high_lock) ... __drain_all_pages() { drain_pages_zone() { /* read pcp->count, it's 0 here */ count = READ_ONCE(pcp->count) /* 0 means nothing to drain */ /* update pcp->count */ pcp->count += alloced << order; ... ... spin_unlock(&pcp->lock); In this case, after calling zone_pcp_disable() though, there are still some pages in pcp_list. And these pages in pcp_list are neither movable nor isolated, offline_pages() gets stuck as a result. Solution: Expand the scope of the pcp->lock to also protect pcp->count in drain_pages_zone(), to ensure no pages are left in the pcp list after zone_pcp_disable() [1] https://lore.kernel.org/linux-mm/6a07125f-e720-404c-b2f9-e55f3f166e85@fujitsu.com/ Link: https://lkml.kernel.org/r/20240723064428.1179519-1-lizhijian@fujitsu.com Fixes: 4b23a68f95 ("mm/page_alloc: protect PCP lists with a spinlock") Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> Reported-by: Yao Xingtao <yaoxt.fnst@fujitsu.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Hildenbrand <david@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>		2024-07-26 14:33:09 -07:00
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damon
kasan
kfence
kmsan
backing-dev.c
balloon_compaction.c
bootmem_info.c
cma.c
cma.h
cma_debug.c
cma_sysfs.c
compaction.c
debug.c
debug_page_alloc.c
debug_page_ref.c
debug_vm_pgtable.c
dmapool.c
dmapool_test.c
early_ioremap.c
execmem.c
fadvise.c
fail_page_alloc.c
failslab.c
filemap.c
folio-compat.c
gup.c
gup_test.c
gup_test.h
highmem.c
hmm.c
huge_memory.c	mm/huge_memory: avoid PMD-size page cache if needed	2024-07-26 14:33:09 -07:00
hugetlb.c
hugetlb_cgroup.c
hugetlb_vmemmap.c
hugetlb_vmemmap.h
hwpoison-inject.c
init-mm.c
internal.h
interval_tree.c
io-mapping.c
ioremap.c
Kconfig
Kconfig.debug
khugepaged.c
kmemleak.c
ksm.c
list_lru.c
maccess.c
madvise.c
Makefile
mapping_dirty_helpers.c
memblock.c
memcontrol-v1.c
memcontrol-v1.h
memcontrol.c
memfd.c
memory-failure.c
memory-tiers.c
memory.c	mm: fix old/young bit handling in the faulting path	2024-07-26 14:33:09 -07:00
memory_hotplug.c
mempolicy.c
mempool.c
memremap.c
memtest.c
migrate.c
migrate_device.c
mincore.c
mlock.c
mm_init.c
mm_slot.h
mmap.c
mmap_lock.c
mmu_gather.c
mmu_notifier.c
mmzone.c
mprotect.c
mremap.c
mseal.c
msync.c
nommu.c
oom_kill.c
page-writeback.c
page_alloc.c	mm/page_alloc: fix pcp->count race between drain_pages_zone() vs __rmqueue_pcplist()	2024-07-26 14:33:09 -07:00
page_counter.c
page_ext.c
page_idle.c
page_io.c
page_isolation.c
page_owner.c
page_poison.c
page_reporting.c
page_reporting.h
page_table_check.c
page_vma_mapped.c
pagewalk.c
percpu-internal.h
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c
pgalloc-track.h
pgtable-generic.c
process_vm_access.c
ptdump.c
readahead.c
rmap.c
rodata_test.c
secretmem.c
shmem.c
shmem_quota.c
show_mem.c
shrinker.c
shrinker_debug.c
shuffle.c
shuffle.h
slab.h
slab_common.c
slub.c
sparse-vmemmap.c
sparse.c
swap.c
swap.h
swap_cgroup.c
swap_slots.c
swap_state.c
swapfile.c
truncate.c
usercopy.c
userfaultfd.c
util.c
vmalloc.c
vmpressure.c
vmscan.c
vmstat.c
workingset.c
z3fold.c
zbud.c
zpool.c
zsmalloc.c
zswap.c